This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The objective of this project is to develop and test a fully implantable vestibular prosthesis in an animal model that is close to the human target population for a rehabilitative prosthesis. We have chosen to work with 10 highly trained adolescent Rhesus monkeys, Macaca Mulatta, because of the close similarity of this species to humans in terms of anatomy, physiology and behavior. In addition, much is known about the vestibular system in primates that can be applied productively to the design and execution of our study.